Data recording method

ABSTRACT

A data recording method is provided in which the time required for recording/reproduction of system logs for each partition is shortened for a tape format having plural partitions. In recording data on an azimuth track on a magnetic tape having a tape format having plural partitions, using a rotary head, the system logs of each partition are recorded in a system region of a leading side partition P1.

This is a division of application Ser. No. 08/507,670 filed Jul. 25,1995.

BACKGROUND OF THE INVENTION

This invention relates to a method and apparatus for recording datatransmitted from, e.g., a computer on an azimuth track of a magnetictape by a rotary head.

In a computer, it is frequently practiced to transfer data recorded on,e.g., a hard disc to a data recorder termed a data streamer, e.g., onceevery day for protecting the data.

Up to now, a conventional analog audio tape recorder has preferentiallybeen used as the above data recorder. However, with the analog audiotape recorder, the amount of consumption of the magnetic tape isincreased excessively, while data recording and transfer becometime-consuming because of the low data recording rate. In addition,since high-speed retrieval is not feasible with the analog audio taperecorder, searching or locating of a data start portion is alsotime-consuming.

Thus it has been practiced to use a helical-scan digital audio taperecorder employing a rotary head, or a so-called DAT, as the datarecorder.

When employing the DAT as the tape recorder, data from a host computerare converted into data of a DAT format before being recorded. With theDAT format, each frame is constituted by two azimuth tracks T_(A), T_(B)formed during one complete revolution of two heads with differentazimuth angles, and 16-bit PCM audio data are recorded by aninterleaving technique with one frame as a recording unit, as shown inFIG. 1. Each track is made up of 196 blocks, each block consisting of 36bytes. Of these blocks, both terminal 34 blocks are sub-areas, with themid 128 blocks being a main area.

Each sub-area is divided, beginning from one track end, into a mergingportion, a preamble portion for sub-code PLL, a first subcode portion, apost-ample portion, a gap portion between adjacent blocks, automatictrack finding (tracking) signal portion or ATF portion, a gap portionbetween adjacent blocks, a preamble portion for data PLL, a pre-ambleportion for adjacent blocks, an ATF signal portion, a gap portionbetween adjacent blocks, a preamble portion for subcode PLL, a secondsubcode portion, a postamble portion, a gap portion between adjacentblocks and a merging portion. Each of the first and second subcodeblocks is made up of 8 blocks, with the remaining portions being made upof respective pre-set number of blocks.

The main area is made up of 128 blocks. Each data block has one byteeach of the synchronization signal, PCM.ID, block address and theparity, beginning from its leading end. Main data is arrayed in the nextfollowing 32 bytes, as shown in FIG. 2.

If the data is audio signals, the main data is 16-bit PCM data for theleft channel and 16-bit PCM data for the right channel. The 16-bit maindata are interleaved in the main areas of two tracks constituting aframe and arrayed along with parity Q data, as shown in FIG. 3. In thiscase, about 5760 bytes of data are recorded in the main area of oneframe.

By dividing a track into the main area and the sub-area, post-recordingmay be made with the DAT format, using the sub-area.

The construction of the error correction code for main data in the DATformat is the product code as shown in FIG. 4, with the code plane beingmade up of four sub-planes per track. Each sub-plane is coded in C1 andC2 directions.

If the data recorder is employed as a data recorder, data transmittedfrom a host computer is converted to 16-bit data which is treated in thesame way as the PCM data and formatted for recording in a one-frame mainarea. In this case, 2-byte 16-bit data for the L and R channels areused, of which upper four bits, for example, are recorded as format IDand the remaining eight bits are recorded as a logical frame number. Theformat ID indicates the format proper to the data recorder. Logicalframe numbers of 1 to 23 are affixed to each of 23 frames as a unit.

As a format of a data recorder employing such DAT, the formats DDS andDDS2, for example, are prescribed under the standard of the EuropeanComputer Manufacturers Association (ECMA).

With the DDS or DDS2 format, a device region from a physical tapebeginning position or physical beginning of tape (PBOT) up to a logicaltape beginning position or logical beginning of tape (LBOT) isprescribed in a leading area consecutive to the leader tape as being aregion for effecting tape loading and unloading. The device region isfollowed by a reference region and a system region. The reference regionis used as a physical reference for recording a system log (hysteresisinformation) in the system region. A data region for data recording isrecorded next to the system region, and an end-of-data (EOD) region isrecorded next to the data region.

The DDS2 format also provides a two-partition tape having two partitionsP1 and P2 each having a reference region, a system region, a data regionand an EOD region. The system log, that is the hysteresis information,is recorded in the system region of each of the partitions P1 and P2.The system log is recorded by multiplex recording in a sub-code regionof the system area in the form of a pack.

With the above-described DDS or DDS2 format, the system log for eachpartition is individually recorded in each system region of each of thepartitions. Thus it becomes necessary to access the system regions whenloading/unloading the tape, thereby consuming a lot of time forloading/unloading.

Since the system region is recorded or reproduced a number of times,tape damage become excessive thus necessitating multiplex recording.Since the error correction coding is not provided for the sub-coderegion, the sub-code region is lower in reliability than the main data.

As for the firmware, accessing of data recorded by multiplex recordingfor improving reliability consumes a lot of time. In effect, checkingcan be made only up to the frame time limit. In addition, the sorts ofitems that can be written are limited, if in the form of the pack.

SUMMARY OF THE INVENTION

It is therefore an object of the present invention to provide a datarecording method for recording data in an azimuth track on a magnetictape by a rotary head in accordance with a tape format having pluralpartitions each of which has at least a system region and a data region,in which the time required for recording/reproducing the system log foreach partition may be reduced.

It is another object of the present invention to provide a datarecording method for recording data in an azimuth track on a magnetictape by a rotary head in accordance with plural tape formats each havingplural partitions each of which has at least a system region and a dataregion, in which the system logs are stored in a manner adapted to therespective tape formats.

It is still another object of the present invention to provide a datarecording method in which the system logs may be improved inreliability.

In one aspect, the present invention provides a method for recordingdata in an azimuth track on a magnetic tape by a rotary head inaccordance with a tape format having plural partitions, which methodconsists in recording the tape hysteresis information for each partitionin a system region of a leading side partition.

In another aspect, the present invention provides a method for recordingdata in an azimuth track on a magnetic tape by a rotary head inaccordance with a tape format having plural partitions each of which hasat least a system region and a data region, which method consists inrecording the tape hysteresis information for each partition in a systemregion of a leading side partition.

In a further aspect, the present invention provides a data recordingmethod consisting in splitting each track into a main data region andmerging regions on both sides of the main data region, splitting themain data region of each track into plural blocks, splitting each blockinto plural portions, recording synchronization signals in the firstportion of each block, recording the subcode in the second portion,recording main data in the third portion, and recording the tapehysteresis information for each partition in the system region of aleading side partition as the subcode.

In a further aspect, the present invention provides a data recordingmethod consisting in splitting each track into a main data region andmerging regions on both sides of the main data region, splitting themain data region of each track into plural blocks, splitting each blockinto plural portions, recording synchronization signals in the firstportion of each block, recording the subcode in the second portion,recording main data in the third portion, and recording the tapehysteresis information for each partition in the system region of aleading side partition as the main data.

In a further aspect, the present invention provides a method forrecording data in an azimuth track on a magnetic tape by a rotary headin accordance with a plurality of tape formats each having pluralpartitions, which method consists in discriminating the tape formats ofthe magnetic tape, recording the tape hysteresis information of eachpartition of the magnetic tape of a first tape format in a system regionof each partition, and recording the tape hysteresis information foreach partition ill the system region of the leading side partition ofthe magnetic tape of the second tape format.

In a further aspect, the present invention provides a method forrecording data in an azimuth track on a magnetic tape by a rotary headin accordance with a plurality of tape formats each having pluralpartitions each having at least a system region and a data region, whichmethod consists in discriminating the tape format of a magnetic tape,recording the tape hysteresis information for each partition of amagnetic tape of a first tape format in the system region of eachpartition, and recording the tape hysteresis information for eachpartition of a magnetic tape having the second tape format on the systemregion of the leading side partition.

In a further aspect, the present invention provides a data recordingmethod for the magnetic tape of the second tape format which methodconsists in splitting a track of each magnetic tape of the second tapeformat into a main data region and merging regions on both sides of themain data region, splitting the main data region of each track into aplurality of blocks, recording a synchronization signal, a subcode andmain data in first, second and third portions of each block,respectively, and recording the tape hysteresis information for eachpartition in a system regions of the partition as the subcode.

In yet another aspect, the present invention provides a data recordingmethod for a magnetic tape of the second tape format which methodconsists in splitting each track into a main data region and mergingregions on both sides of the main data region, splitting the main dataregion of each track into a plurality of blocks, splitting each blockinto plural portions, recording a synchronization signal, a subcode andmain data in first, second and third portions of each block, andrecording the tape hysteresis information for each partition in a systemregions of the partition as the main data.

With the data recording method of the present invention, when recordingdata on an azimuth track on a magnetic tape by a rotary head inaccordance with a tape format having plural partitions, the hysteresisinformation for each partition is recorded in the system region of theleading side partition, thereby reducing the time required forrecording/reproducing the system log for each partition.

The tape hysteresis information for each partition is recorded as asubcode in the system region of the leading side partition as thesubcode, or the tape hysteresis information for each partition isrecorded as a main data in the system region of the leading sidepartition as the main data.

Also the tape format of the magnetic tape is discriminated so that, forthe magnetic tape of the first tape format, the tape hysteresisinformation for each partition is recorded in the system region of eachpartition, while, for the magnetic tape of the second tape format, thetape hysteresis information is recorded in the system region of theleading side partition, thereby enabling recording of system logsadapted to respective tape formats. The tape hysteresis information foreach partition is recorded in the system region of the partition as thesubcode.

Alternatively, the tape hysteresis information of each partition isrecorded in the system region of the partition as main data, therebyimproving system log reliability.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a DAT format.

FIG. 2 shows a block format for main data in the DAT format.

FIG. 3 shows data array in the DAT format in which the interleavingtechnique is applied.

FIG. 4 shows the construction of the error correction coding of maindata in the DAT format.

FIG. 5 is a block circuit diagram showing the construction of a datastreamer for carrying out the data recording method according to thepresent invention.

FIG. 6 shows the track format of a magnetic tape for data recording bythe data streamer.

FIG. 7 shows a data construction for one track of data recorded on amagnetic tape by the data streamer.

FIG. 8 shows a data construction for one unit of 46 tracks of datarecorded on a magnetic tape by the data streamer.

FIG. 9 shows a tape format of a magnetic tape for recording the data bythe data streamer.

FIG. 10 shows a data format of a 2-partition magnetic tape.

FIG. 11 illustrates the tracking error detection principle by a trackingcontroller in the data streamer.

FIG. 12 is a schematic block diagram showing the construction of mainportions for format discrimination in case of handling magnetic tapes ofplural tape formats in the data streamer.

FIG. 13 is a flow chart for illustrating the control operation of thetwo sorts of tape formats.

FIG. 14 shows another tape format of the two-partition magnetic tape.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to the drawings, certain preferred embodiments of the datarecording method of the present invention will be explained in detail.

The data recording method of the present invention is carried out by adata streamer as shown for example in FIG. 5.

The data streamer causes data to be recorded on and reproduced from anazimuth track on a magnetic tape by a rotary magnetic head and includesan interfacing controller 10 for data exchange with outside and arecording system signal processing section 20 for processing input datasupplied to the data streamer via the interfacing controller 10 forconversion into signals of a pre-set format. The data streamer alsoincludes a recording/reproducing section 30, a reproducing system signalprocessing section 40 and a tracking control section 50. Therecording/reproducing section 30 records a signal supplied from therecording system signal processing section 20 by a pair of rotarymagnetic heads 31A, 31B on azimuth tracks on a pair of rotary magneticheads 31A, 31B and reproduces the signals recorded on the azimuth tracksby the rotary magnetic heads 31A, 31B. The reproducing system signalprocessing section 40 processes the playback signal from therecording/reproducing section 30 to reproduce the original data, whilethe tracking control section 50 controls the tape running system of therecording/reproducing section 30.

In the present data streamer, the recording/reproducing section 30 has arotary drum 31 made up of a pair of rotary magnetic heads 31A, 31Barranged at an angle of 180° relative to each other. On the peripheralsurface of the rotary drum 31 is placed the magnetic tape 32 over anangle substantially equal to 90° and is run at a pre-set runningvelocity. During each complete revolution of the rotary drum 31, twoazimuth tracks T_(A), T_(B) on the magnetic tape 32 are scanned by therotary magnetic heads 31A, 31B for recording/reproducing the signals, asshown in FIG. 6.

The data streamer splits one track into three regions, namely a maindata region and two merging regions on both ends of the data region. Thedata streamer also splits the main region into 64 blocks, each bockbeing made up of 195 bytes. The data streamer divides each block intofour portions, namely a one-byte first portion for recording asynchronization signal, a six-byte second portion for recording thesub-code and a block address, a 2-byte third portion for recording theheader parity and a 186-byte fourth portion for recording data. In eachblock of the main data region, the sub-code and the block address arerecorded along with data.

To the 186-byte data recorded in the fourth portion are appendedcorrection codes (product codes) C2, C1, as shown in FIG. 7. Thecorrection code C1 is appended to and recorded with the block-based maindata, while the error correction code C2 is divided into two portionswhich are recorded in both end portions of the main data region of eachtrack.

The data streamer employs a code construction for error correction inwhich two tracks or 128 blocks make up one frame and 46 tracks or 23frames make up one unit or group. The error correction code C2 for datastrings along the track direction is arrayed and recorded on both endsof the tracks and the error correction code C3 for the data string alongthe track width is allocated for the last two of the 46 tracks, as shownin FIG. 8. The index information for partitioning a series of data isappended at a one-unit interval.

As the sub-code, a separator count, which is the information concerningthe partitioning of the main data, a record count indicating the numberof records, an area ID indicating each region defined on the tapeformat, frame numbers indicating the absolute positions of the recordingunits, the group counts indicating the number of recording units, andthe check sum, are recorded.

In the present data streamer, similarly to the DDS2 format, there isdefined, as a region for effecting loading and unloading of the magnetictape, a device region in a leading region in direct succession to theleader tape. The device region is a region from a physical tapebeginning position or physical beginning of tape (PBOT) up to a logicaltape beginning position or logical beginning of tape (LBOT), as shown inFIG. 9. The device region is followed by a reference region and a systemregion. The reference region is used as a physical reference forrecording the system log (hysteresis information) in the system region.A data region for recording the data is provided next to the systemregion, and an end-of-data (EOD) region is recorded next to the dataregion. The present data streamer provides a two-partition tape havingtwo partitions P1 and P2 each having a reference region, a systemregion, a data region and an EOD region, as shown in FIG. 10.

The system logs of the partitions P1 and P2 are recorded in the systemregion of the partition P1. By recording the system logs (hysteresisinformation) in the system region of the partition P1, it suffices torecord/reproduce only the system region of the partition P1, therebyallowing to reduce the time required in recording/reproducing the systemlogs of the respective partitions.

In the present data streamer, the interfacing controller 10 exchangesdata over a bus 11 with an external host computer, not shown, whiletransmitting data supplied from the host computer to the recordingsystem signal processing section 20 and also transmitting datareproduced by the reproducing system signal processing section 40 to thehost computer.

The recording system signal processing section 20 has an index appendingunit 21 and a subcode generator 22 fed with data entering theinterfacing controller 10, and an error code generator 23 fed with maindata to which the index information has been appended by the indexappending circuit 21. The processing section also includes a sub-codeappending circuit 24 fed with the main data from the error correctioncode generator 23, having the error correction code appended thereto bythe error correction code generating circuit 23, and with the subcodeand the block address from the subcode generating circuit 22. Theprocessing section also-includes a header parity appending circuit 25fed with main data to which the subcode and the block address have beenappended by the subcode appending circuit 24. The processing section 20also includes a modulating circuit fed with main data to which theheader parity has been appended by the header parity appending circuit25, and a synchronization signal appending circuit 27 fed with main dataconverted into 10-bit data by the modulating circuit 26. The processingsection 20 also includes a merging bit appending circuit 28 fed withmain data to which the synchronization signal has been appended by thesynchronization signal appending circuit 27, and a recording amplifier29 fed with the main data to which the merging data has been appended bythe merging bit appending circuit 28.

The index appending circuit 21 appends the index information to inputdata supplied thereto via the interfacing controller 10. The indexinformation is used for splitting the input data in terms of units eachconsisting of the above-mentioned 46 tracks or 23 frames.

The error correction code generator 23 includes a memory 49, a C3encoder 23A, a C2 encoder 23B and a C1 encoder 23C.

In the error code generator 23, the memory 49 temporarily stores maindata, to which the index information has been appended by the indexinformation appending circuit 21, in terms of units. The C3 encoder 23Agenerates, for the unit-based main data stored in the memory 49, anerror correction code C3 for data strings along the track width, andallocates the error correction code C3 to the last two of the one-unit46 tracks. The C2 encoder 23B also generates an error correction code C2for data strings along the track direction, splits the error correctioncode C2 in two portions and allocates the portions to both end portionsof the main data region. In addition, the C1 encoder 23C generates theerror correction code C1 on the block basis.

The subcode appending circuit 24 appends the block address and thesubcode supplied from the subcode generator 22 to the main data to whichthe error correction codes C3, C2 and C1 have been appended by the errorcorrection code generator 23. The subcode and the block address areallocated in this manner to the second portion of each block.

The subcode generator 22 includes first and second subcode generatingcircuits 22A and 22B and a system log generating circuit 22C.

The first subcode generating circuit 22A of the subcode generator 22generates e.g., record counts indicating the number of records orseparator counts as the main data partitioning information based upondata supplied thereto via the interfacing controller 10. The secondsubcode generating circuit 22B automatically generates area IDsindicating respective regions defined on a tape format, frame numbers,group counts indicating the number of recording units or the check sum,along with the block addresses. The system log generating circuit 22Calso generates the system log (hysteresis information) for each of thepartitions P1 and P2 prescribed as the tape formats.

The header parity appending circuit 25 generates 2-byte parity for errordetection for the block address and the subcode appended to the maindata by the subcode appending circuit 24 and appends the 2-byte parityto the main data. The 2-byte parity is allocated in this manner to thethird portion of each block.

The modulating circuit 26 converts the main data, to which the headerparity and the block address have been appended by the header parityappending circuit 25, from 8-bit data to 10-bit data, on the byte basis,so that the dc level of the recording signals will be maintained at asubstantially zero level.

The synchronization signal appending circuit 27 appends thesynchronization signal, on the block basis, to the main data convertedby the modulating circuit 26 into the 10-bit data. The synchronizationsignal is allocated in this manner to the first portion of each block.

The merging bit appending circuit 28 appends merging bits to main data,to which the synchronization signal has been appended by thesynchronization signal appending circuit 27, on the track basis. Themerging region is annexed in this manner to both sides of each main dataregion on the track basis.

The main data, to which the merging bits have been appended on the trackbasis by the merging bit appending circuit 28, are supplied via therecording amplifier 29 to the recording/reproducing section 30.

The data streamer, having the above-described recording system signalprocessing section 20, splits one track into three regions, namely amain data region and two merging regions on both ends of the dataregion. The data streamer also splits the main region into 64 blocks,each block being made up of 195 bytes. The data streamer divides eachblock into four portions, namely a one-byte first portion for recordinga synchronization signal, a six-byte second portion for recording thesub-code and a block address, a 2-byte third portion for recording theheader parity and a fourth portion for recording the data. In each blockof the main data region, the sub-code and the block address are recordedalong with the data. As the sub-code, a separator count, which is theinformation concerning the partitioning of the main data, a record countindicating the number of records, an area ID indicating each regiondefined on the tape format, frame numbers, the group counts indicatingthe number of recording units, and the check sum, may be recorded. Thetrack utilization efficiency may be increased by splitting each trackinto a main data region and merging regions on both sides of the maindata region and recording the subcode along with the main data in themain data region. In addition, by recording the two-byte parity forsubcode error correction in the third portion of each block, subcodereliability and hence the track utilization efficiency of a datarecording medium may be improved.

It is also possible with the present data streamer to generate the errorcorrection codes (product codes) C2 and C1 for 186-byte data to berecorded in the fourth portion, append the error correction code C1 tothe block-based main data for recording, and to split the errorcorrection code C1 in two portions for recording in two terminalportions of the main data region. The block-based main data reliabilitymay be improved by recording the error correction code C1 in this mannerfor each block, while the track-based main data reliability may beimproved by recording the error correction code C2 for each block. Inaddition, by splitting the error correction code C2 and recording theseportions on both end portions of the main data region for each track,the main data region may be separated from the slide contact start/ endportion with respect to the rotary head to reduce the error otherwiseproduced in the data of the main data region.

It is also possible with the present data streamer to exploit an errorcorrecting code construction in which 46 tracks, that is 23 frames, aregrouped in one unit, each frame being two tracks or 128 blocks, recordthe error correction code C2 for data strings along the track directionon both sides of each track and to allocate the error correction code C3for the data strings along the track width in the last two of the 46tracks. In addition, the index information for partitioning a series ofdata may be appended for each unit for recording. By recording the errorcorrection code C2 for data strings along the track direction on bothsides of each track, the main data may be rendered less susceptible todestruction for lowering the probability of error occurrence in the maindata, so that it becomes possible to positively correct errors in themain data by the error correction code C3 for the data strings along thetrack width.

In addition, with the present data streamer, both the system logs(hysteresis information) of the partitions P1 and P2 are recorded assubcode in the system region of the partition P1. By recording both thesystem logs of the partitions P1 and P2 in the system region of thepartition P1, the access time may be shortened and a data streamershowing good operability may be achieved.

The reproducing system signal processing section 40 in the present datastreamer includes a synchronization signal detection circuit 42, fedwith the playback signal reproduced from the azimuth track of themagnetic tape 32 by the recording/reproducing section 30 via a playbackamplifier 41, and a demodulating circuit 43 fed with bi-level playbackdata from the synchronization signal detection circuit 42. Theprocessing section 41 also includes a subcode separating circuit 45 fedwith the playback data, converted into 8-bit data from the 10/8demodulating circuit 43, via a header parity check circuit 44, an errorcorrection unit 46 fed with the playback data freed of the subcode bythe subcode separating circuit 45 and an index separating circuit 47 fedwith playback data error-corrected by the error correcting circuit 46.

The synchronization signal detection circuit 42 of the reproducingsystem processing section 40 detects the synchronization signal in theplayback signal supplied from the recording/reproducing section 30 viathe playback amplifier 41 and converts the playback signal into abi-level signal by clocks synchronized with the synchronization signalfor generating playback data.

The demodulating circuit 43 converts the playback data supplied from thesynchronization signal detection circuit 42 from the 10-bit data to the8-bit data. Thus the demodulating circuit effects 10/8 conversion whichis a counterpart operation of the 8/10 conversion by the modulatingcircuit 26.

The parity check circuit 44 effects parity check of the subcode and theblock address using the above-mentioned 2-byte header parity. In thesubcode separating circuit 45, the correct subcode, parity-checked bythe parity check circuit 44, is separated from the playback data, so asto be transmitted to, e.g., a system controller, not shown.

The error correction unit 46 includes the above-mentioned memory 49, aC1 decoder 46A, a C2 decoder 46B and a C3 decoder 46C.

The memory 49 of the error correction unit 46 temporarily stores themain data, to which the index information has been appended, with46-track or 23-frame main data portions as a unit of storage. The memory49 is co-used by the error correction unit 23 of the recording systemsignal processing section 20.

The C1 decoder 46A effects data correction on each block of the maindata, stored unit-by-unit in the memory 49, using the error correctioncode C1 appended on the block basis. On the other hand, the C2 decoder46B effects data correction on each data string along the trackdirection of the unit-based main data, which has been error-corrected bythe C1 decoder 46A, using the error correction code C2 appended to bothend portions of the main data region for each track. In addition, the C3decoder 46C effects data correction on each data string along the trackwidth of the unit-based main data, which has been error-corrected by theC2 decoder 46B, using the error correction code C3 allocated to the lasttwo of the one-unit 46 tracks.

The index separating circuit 47 separates the index information from theunit-based main data, which has been error-corrected by the errorcorrecting unit 46, and routes the separated index information to e.g.,a system controller, not shown.

In the present data streamer, having the above-described reproducingsystem signal processing section 40, error correction of the main datamay be achieved positively to give highly reliable main data byeffecting error correction by the error correction unit 46 using theblock-based error correction code C1, track-based error correction codeC2 and the unit-based error correction code C3.

In the present data streamer, the tracking control section 50 includes ablock address detection circuit 51 fed with the block address via theheader parity check circuit 44 from the reproducing system signalprocessing section 40, and a PG detection circuit 52 fed with the PGpulse from the block address detection circuit 51. The tracking controlsection 50 also includes a time detection circuit 53 fed with detectionoutputs of the block address detection circuit 51 and the PG detectioncircuit 52, a tracking servo circuit 54 fed with a detection output ofthe time detection circuit 53 and a capstan driving circuit 55 fed withan output of the tracking servo circuit 54.

In the tracking control section 50, the block address detection circuit51 detects the correct block address, parity-checked by the headerparity check circuit 44, and routes a detection output indicating thedetection timing to the time detection circuit 53. The PG detectioncircuit 52 detects the PG pulse indicating the rotational phase of therotary drum 31 supplied from the recording/reproducing section 30 androutes a detection output indicating the detection timing to the timedetection circuit 53. The time detection circuit 53 detects the timewhich elapses since the timing of detection of the pre-set block addressby the block address detection circuit 51 until the timing of detectionof the PG pulse by the PG detection circuit 52. Supposing that anazimuth track on the magnetic tape 32 is scanned by the rotary magneticheads 31A, 31B having a pre-set rotational phase, the scanning distancefrom the tape edge of a track to a pre-set block is L in thejust-tracking state, whereas the scanning distance is varied by ±Δresponsive to a tracking error, if there be any. Thus the time detectedby the time detection circuit 53 is varied depending on the trackingerror as from the time for the just-tracking state.

The tracking servo circuit 54 detects the time difference between thereference time corresponding to the time for the just-tracking state andthe time detected by the time detection circuit 53, that is the trackingerror, and controls the capstan driving circuit 55 driving the capstanmotor of the tape running system of the recording/reproducing section30, based upon the detection output, so that the tracking error will bereduced to zero.

The data streamer, having the above-described tracking control section50, is capable of effecting tracking control without having to recordtracking-control ATF signals on the magnetic tape. Since there is nonecessity in this manner to provide a recording portion for recordingtracking-control ATF signals, the data volume of the main data can becorrespondingly increased for further enhancing the track utilizationefficiency..

With the above-described data streamer, the system logs for thepartitions P1 and P2, generated by the system log generating circuit22C, are recorded by the sub-code appending circuit 24 in the systemregion of the partition P1 as the subcode. It is however possible tosupply the system logs of the partitions P1 and P2, generated by thesystem log generating circuit 22C, to the C2 encoder 23B, and to recordthe system logs as main data in the system region of the partition P1.

If the system logs of the partitions P1 and P2 are recorded as main datain the system region of the partition P1, the system log may also becorrected for errors by the error correction code C2, thus raising thesystem log reliability.

The present data streamer may also be configured to handle magnetictapes of plural tape formats. In such case as shown in FIG. 12, tapeformat discrimination holes 35 are provided in a tape cartridge 34loaded on the recording/reproducing section 30, so as to be detected bya discrimination hole detector 61, a detection output of which is fed toa system controller 62. The system controller then performs formatdiscrimination of the magnetic tape 32 and effects control depending onrespective formats in accordance with the flow chart shown in FIG. 13.

When the tape cartridge 34 housing the magnetic tape 32 therein isloaded on the recording/reproducing section 30, the system controller 62detects, at step S1, the tape format discriminating hole 35 provided inthe tape cartridge 34 is detected by the tape format discrimination holedetector 61. At, the next step S2, the system controller effects formatdiscrimination of the magnetic tape 32 based upon the detection output.

If the system controller 62 judges the tape format to be a first tapeformat or a second tape format at step S2, it, transfers to step S11 orto step S21, respectively.

The first tape format is the conventional DDS2 format, while the secondtape format is the format employed in the above-described embodiment.

At step S11, the system controller 62 causes the magnetic tape 32 to runas far as the system region of the first partition P1. At step S12, thesystem controller 62 reads out the system log information of the firstpartition P1 for storage in a memory. At the next step S13, the systemcontroller 62 causes the magnetic tape 32 to run as far as the systemregion of the second partition P2 and, at the next step S14, reads outthe system log information of the second partition P2 for storage in amemory.

At the next step S15, the system controller 62 performs various controloperations, such as data write/readout, and updates the system log onthe memory depending on the contents of the control operations.

When the system controller 62 accepts an ejection command, it transfersto step S16 and causes the magnetic tape 32 to run as far as the systemregion of the second partition P2. At step S17, the system controller 62records the system log information of the second partition P2 in thesystem region of the second partition P2. At the next step S18, thesystem controller causes the magnetic tape 32 to run as far as thesystem region of the first partition P1. At step S19, the systemcontroller 62 records the system log information of the first partitionP1 in the system region of the first partition P1. The system controller62 then transfers to step S30 and ejects the tape cartridge 34 from therecording/reproducing section 30 to complete the control on the magnetictape 32 of the first tape format.

Thus the system logs of the partitions P1 and P2 are individuallyrecorded in the system regions of the respective partitions of themagnetic tape 32 of the first tape format by a series of operations ofthe steps S11 to S19.

On the other hand, the system controller 62 causes the tape 32 to run atstep S21 as far as the system region of the first partition P1. At stepS22, the system controller reads out the system log information of thefirst partition P1 for storage in a memory.

At step S23, the system controller 62 performs various controloperations, such as data write/readout operations, and updates thesystem logs on the memory depending on the contents of the controloperations.

When the system controller 62 accepts an ejection command, it transfersto step S24 and causes the magnetic tape 32 to run as far as the systemregion of the first partition P1. At step S19, the system controller 62records the system log information of the first partition P1 and thesystem log information of the second partition P2 in the system regionof the first partition P1. The system controller 62 then transfers tostep S30 and ejects the tape cartridge 34 from the recording/reproducingsection 30 to complete the control on the magnetic tape 32 of the secondtape format.

Thus the system logs of the partitions P1 and P2 are individuallyrecorded in the system region of the first partition of the magnetictape 32 of the second tape format by a series of operations of the stepsS21 to S25.

Although the system logs of the partitions P1 and P of the magnetic tape32 of the second tape format may be recorded as the sub-codes in thesystem region of the first partition, the system logs may be protectedby the error correction code C2 if the system logs are recorded as maindata, thereby improving system log reliability.

In the above-described embodiments, a tape format comparable to the DDS2tape format in which the partitions P1 and P2 are each composed of thereference region, system region and the EOD region. However, since thesystem logs of both the partitions P1 and P2 are recorded in the systemregion of the leading side partition P1, it is also possible to employ atape format in which the system region of the trailing side partition P2is omitted to leave only the system region of the leading side partitionP1, as shown in FIG. 14.

What is claimed is:
 1. Recording apparatus for recording informationdata on a tape recording medium having a plurality of partitions, aleading side partition of the tape recording medium being constituted atleast by a system region having recorded therein tape hysteresisinformation for each partition and a data region having said informationdata recorded therein, a partition subsequent to the leading sidepartition being constituted at least by a data region having informationdata recorded therein, the recording apparatus comprising:a rotary headfor recording and/or reproducing data in and/or from the tape recordingmedium; memory means for storing therein the tape hysteresis informationfor each partition read out from the tape recording medium by the rotaryhead; error correcting means for correcting errors in the tapehysteresis information and producing error-corrected tape hysteresisinformation; and control means for performing control for updating thetape hysteresis information stored in the memory means on the basis ofrecording and/or reproduction of data in and/or from the tape recordingmedium, for accessing the leading side partition of the tape recordingmedium following receipt of an ejection command and before ejecting thetape recording medium from the recording apparatus, and for performingcontrol to record the error-corrected tape hysteresis information foreach partition stored in the memory means.
 2. Recording apparatus asclaimed in claim 1, further comprising:a tape hysteresis generator forgenerating the tape hysteresis information for each of said partitionsin the form of subcode; and a subcode appending circuit for appendingthe tape hysteresis information in the form of subcode to theinformation data for recording.
 3. Recording apparatus for recordinginformation data on a tape recording medium having a plurality ofpartitions, a leading side partition of the tape recording medium beingconstituted at least by a system region having recorded therein as maindata tape hysteresis information for each partition and a data regionhaving said information data recorded therein, a partition subsequent tothe leading side partition being constituted at least by a data regionhaving information data recorded therein, the recording apparatuscomprising:a rotary head for recording and/or reproducing data in and/orfrom the tape recording medium; a tape hysteresis information generatorfor generating the tape hysteresis information; an encoder connected tothe tape hysteresis information generator receiving the information dataand the tape hysteresis information and producing a combined output;error correcting means for correcting errors in said combined output ofthe encoder including the tape hysteresis information and producingerror-corrected tape hysteresis information; and control means forperforming control to record the error-corrected tape hysteresisinformation as main data in the system region of the leading sidepartition following receipt of an ejection command and before ejectingthe tape recording medium from the recording apparatus.